01 / THE LONG BURN
More fuel. A shorter life.
A massive star spends its fuel much faster than a Sun-like star. Here, one solar mass gives roughly ten billion years of core hydrogen burning; fifteen gives about twelve million. The clock begins at that burning stage, after the un-timed formation prelude.
The age anchors are rounded, informed by solar-metallicity stellar models. Values between anchors use smooth logarithmic interpolation. The giant phases and aftermath use simplified durations; they are illustrative estimates rather than fitted evolutionary tracks.
Examine the published lifetime grids ↗
02 / THE LAST LIGHT
A cinder, a dense core, or darkness.
The lower-mass route sheds an envelope and leaves a white dwarf. The massive route illustrates core collapse and a selected compact remnant. The control compares possibilities; it does not turn initial mass into a universal neutron-star or black-hole threshold.
The switch near eight solar masses is a storytelling boundary. Real transition cases, mass loss, rotation, composition, and the explosion mechanism complicate it. Small remnants are enlarged, and supernova ejecta are slowed for viewing. A stellar black hole is far smaller than Sagittarius A*. The contraction view reveals an enlarged core inside a fading envelope. The neutron-star beams depict a pulsar-like example. Black-hole disk light follows nonrotating light-bending geometry; gas brightness and inward motion are illustrative, without predicting a returning gas mass or gas history.
Explore the galaxy’s dark heart ↗
03 / THE SECOND STAR
Two clocks. One shared age.
Wide mode lets you choose two starting masses and a separation. Both stars are sampled at the same age, and both orbit their common center of mass: the heavier star traces the smaller orbit. The period readout uses the initial masses and separation, while the visual orbit is accelerated.
The wide example assumes detached stars. The guided 5 + 3 solar-mass pair instead illustrates envelope transfer: four solar masses leave A, two reach B, and two leave the pair. Later donor phases and ages are assumed. Separation changes the initial orbital period, without predicting whether a real system transfers stably or merges.
Follow the binary-star evidence ↗
04 / A DIFFERENT EXPLOSION
A white dwarf can be destroyed.
The third binary story begins with an existing white dwarf and a giant, not two newborn stars. An assumed retained transfer rate makes the white dwarf gain 0.27 solar masses in 2.7 million years. At the chosen 1.37-solar-mass trigger, this example ends in a thermonuclear supernova, leaving no white dwarf, neutron star, or black hole at its center.
Those numbers define a teaching scenario, not a measured system or forecast. Other binaries can produce novae, retain different amounts of gas, merge, or avoid an explosion. The initial orbit is held for illustration and stops at the explosion; orbital disruption, donor response, accretor rejuvenation, tides, and later companion evolution are not calculated.
Compare the two supernova mechanisms ↗
